[vtkusers] vtkPolyDataConnectivityFilter Help

[Sylvain Jaume]

Hi Mike,

You may want to do:

vtkPolyDataConnectivityFilter *connections =  
vtkPolyDataConnectivityFilter::New();
connections->SetInput(data);
connections->SetExtractionModeToAllRegions();
connections->ColorRegionsOn();
connections->Update();

  unsigned int numRegions = connections->GetNumberOfExtractedRegions();
  vtkClipPolyData *clip = vtkClipPolyData::New();
  clip->SetInput(connections->GetOutput() );

  for (unsigned int i = 0; i < numRegions; ++i)
  {
      std::cout << "----------- Region Number " << i << "  ----------" 
<< std::endl;
      clip->SetValue( (float) i );
      clip->Update();
      clip->GetOutput()->PrintSelf(std::cout, 1);
  }

You don't need  clip->GenerateClipScalarsOff();

Cheers,
Sylvain

Mike Jackson wrote:

>
> On Nov 23, 2005, at 5:18 PM, Sylvain Jaume wrote:
>
>>
>> You could set ColorRegionsOn in vtkPolyDataConnectivityFilter.
>> Then use vtkClipPolyData with SetValue set to the region id (i in  
>> your code).
>>
>> Cheers,
>> Sylvain
>
>
> I gave that a try, looking extensively at the docs and this is what I  
> have.
> //Assume data is of type vtkPolyData which has been through a smoothing
> // and a Decimation, just prior to this.
>   vtkPolyDataConnectivityFilter *connections =  
> vtkPolyDataConnectivityFilter::New();
>   connections->SetInput(data);
>   connections->SetExtractionModeToAllRegions();
>   connections->Update();
>
>   /// Loop on each Region
>   unsigned int numRegions = connections->GetNumberOfExtractedRegions();
>   vtkClipPolyData *clip = vtkClipPolyData::New();
>   vtkImplicitBoolean *func = vtkImplicitBoolean::New();
>   clip->SetInput(connections->GetOutput() );
>   clip->SetClipFunction(func);
>   clip->GenerateClipScalarsOff();
>
>   for (unsigned int i = 0; i < numRegions; ++i)
>   {
>       std::cout << "----------- Region Number " << i << "  ----------" 
> << std::endl;
>       clip->SetValue( (float) i );
>       clip->Update();
>       clip->GetOutput()->PrintSelf(std::cout, 1);
>   }
>
> When the prints go by the number of polys, vertices, cells... are all  
> Zero. Any idea what I am doing wrong?
>
> I think I am getting confused about the implicit function and whether  
> or not to have GenerateClipScalarsOff or GenerateClipScalarsOn.
> ---
> Mike Jackson
> mike _at_ bluequartz dot net
>
>
>